This invention relates to a relief valve for a filter that also acts as a seal between a filter cartridge assembly and a housing of the filter.
A typical spin-on filter includes a housing that has a tapping plate with a threaded aperture. The threaded aperture provides an outlet for the filter and is screwed onto a mounting block stud to fluidly connect the filter with an engine oil circulation system, for example.
A filter cartridge assembly is arranged within the housing to filter debris in the oil. The filter cartridge assembly must seal relative to the housing to ensure that oil flows through the filter cartridge assembly under desired conditions. Some filter designs utilize a distinct, separate elastomeric gasket to seal the filter cartridge assembly to the tapping plate. Other filter designs rely upon a plastic-to-metal or metal-to-metal sealing between the filter cartridge assembly and the tapping plate. Using a separate elastomeric gasket as a component in the filter can increase cost and complicate assembly. Relying upon metal or a rigid plastic to seal against the tapping plate requires very good sealing surfaces and alignment.
What is needed is a good seal between the filter cartridge assembly and the tapping plate that does not add cost or complicate assembly of the filter.